Houdini 18.5 Properties

Viewport properties

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Overview

These properties control viewport display of objects. They are in the Viewport folder in the list of properties available under the Render Properties tab of the Edit parameter interface window. Select a node, and in the parameter editor click the Gear menu and choose Edit rendering properties to add or remove properties to a render driver, camera, object, shader, or properties node.

Properties

OpenGL Uniform Fog

These options can be placed on any node, and referenced through the Fog Node option in the Display Options dialog. This allows them to be animated.

Uniform Fog

Add uniform fog to the viewport.

Fog Density

The density of the uniform fog.

Fog Opacity

An opacity modifier on the uniform fog to quickly dial the effect up or down.

Fog Color

The color of the uniform fog.

Fog Depth Range

Where the fog begins and ends, in world units from the camera. For Uniform fog, the depth values are clamped to these depths. Nearer the fog start there will be no fog, and farther end the fog will hold at that maximum fog value.

Fog Clip Distance

The maximum distance that uniform fog is applied. Objects farther than this have no fog applied. This is useful for avoiding fog on background plates.

Fog Height Mode

  • off – Fog is applied evenly regardless of height.

  • above – Fog is only applied above the Fog Height. This simulates a layer of cloud.

  • below – Fog is only applied below the Fog Height. This simulates ground fog.

Fog Height

The cutoff point for fog, in world units, when Fog Height Mode is set to above or below.

Fog Height Falloff

A gradual falloff for fog so the transition between fog and no fog is not as sharp. This is in world units, and affects the fogged area so that at Fog Height there will be no fog. For example, in above mode, the fog density will gradually increase from zero at Fog Height, to Fog Density at Fog Height + Fog Height Falloff.

Fog Sun

Use a directional light in the scene to do simple lighting when in Uniform mode. The direction and color of the light is used to blend between the fog and light colors. The Fog Sun Intensity adjusts the intensity of sun effect.

Fog Sun Bloom

Adjust the extent of the sun’s lighting on uniform fog. Larger values will produce a larger bloom in the direction of the sun, similar to adjusting the roughness on a material. This only affects Uniform fog.

Fog Sun Intensity

Multiply the distant light intensity by this value if Fog Sun is enabled.

OpenGL Volume Fog

These options can be placed on any node, and referenced through the Fog Node option in the Display Options dialog. This allows them to be animated.

Volumetric Fog

Add volumetric fog to the viewport. This requires lights in the scene to illuminate the fog.

Fog Density

The density of the volumetric fog.

Fog Opacity

An opacity modifier on the volumetric fog to quickly dial the effect up or down.

Fog Color

The color of the volumetric fog.

Fog Depth Range

For the Volumetric fog, this range defines where the fog is lit, in world units from the camera. Outside this range no fog effect occurs, so it should tightly bound the lights with Fog Scattering. Making this too large will make the fog look blocky.

Fog Height Mode

  • off – Fog is applied evenly regardless of height.

  • above – Fog is only applied above the Fog Height. This simulates a layer of cloud.

  • below – Fog is only applied below the Fog Height. This simulates ground fog.

Fog Height

The cutoff point for fog, in world units, when Fog Height Mode is set to above or below.

Fog Height Falloff

A gradual falloff for fog so the transition between fog and no fog is not as sharp. This is in world units, and affects the fogged area so that at Fog Height there will be no fog. For example, in above mode, the fog density will gradually increase from zero at Fog Height, to Fog Density at Fog Height + Fog Height Falloff.

Fog Depth Range

For the Volumetric fog types, this range defines where the fog is lit, also in world units from the camera. Outside this range no fog effect occurs, so it should tightly bound the lights with Fog Scattering. Making this too large will make the fog look blocky.

Fog Quality

  • Low Volumetric – Small volume used for lighting, very fast.

  • Medium Volumetric – Medium sized volume used for lighting, balanced between speed and quality.

  • High Volumetric – Large volume used for lighting, high quality.

Fog Intensity

The default light intensity for all lights that do not have the gl_fogintensity property on them. By default this is 1 (all lights contribute to the lit fog). This can be set to zero so that only lights with gl_fogintensity contribute to the lighting.

Fog Scattering

The first value controls the intensity of the lit fog when the light ray is parallel to the viewing direction. The second controls the intensity when the light ray is perpendicular to the viewing direction. Bright light blooms can be reduced by reducing the first value while still keeping god rays visible. This setting only affects Volumetric Fog, and can be overridden per-light with gl_fogscattering property on the light node.

OpenGL Fog Light

These parms can be placed on individual lights to customize how they light volumetric fog.

Fog Light Intensity

Place this property on a light to control how much it illuminates lit volumetric fog. By default all lights have a intensity factor defined by the Fog Intensity display option (or property above). Setting this to zero or less will remove the light from volumetric lighting.

Fog Light Scattering

Place this property on a light to control light scattering on volumetric fog. The first value controls the intensity of the lit fog when the light ray is parallel to the viewing direction. The second controls the intensity when the light ray is perpendicular to the viewing direction. Bright light blooms can be reduced by reducing the first value while still keeping god rays visible.

OpenGL view

Viewport comment

When you attach this property to a camera or light, the comment you set appears in the upper left corner of the viewport when you're looking through the camera/light. This can be useful to document cameras and lights for artists.

View mask

Mask aspect

The aspect of the viewport mask.

Mask opacity

The opacity of the viewport mask.

Mask overlay

The SOP which specifies the geometry to for the mask overlay.

Properties